.github: add CLA workflow

Signed-off-by: Jimmy Zelinskie <jimmy@zelinskie.com>

.github/workflows/cla.yaml

@@ -0,0 +1,28 @@
+name: "CLA Assistant"
+on:
+  issue_comment:
+    types: 
+      - "created"
+  pull_request_target:
+    types: 
+      - "opened"
+      - "closed"
+      - "synchronize"
+
+jobs:
+  CLAssistant:
+    runs-on: "ubuntu-latest"
+    steps:
+      - name: "CLA Assistant"
+        if: "(github.event.comment.body == 'recheck' || github.event.comment.body == 'I have read the CLA Document and I hereby sign the CLA') || github.event_name == 'pull_request_target'"
+        uses: "cla-assistant/github-action@v2.1.3-beta"
+        env:
+          GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+          PERSONAL_ACCESS_TOKEN: "${{ secrets.CLA_ASSISTANT_ACCESS_TOKEN }}"
+        with:
+          remote-organization-name: "authzed"
+          remote-repository-name: "cla"
+          path-to-signatures: "v1/signatures.json"
+          path-to-document: "https://github.com/authzed/cla/blob/main/v1/icla.md"
+          branch: "main"
+          allowlist: "authzedbot,dependabot-bot"